Safety cut-off device for fuel-oil burners.



G. A. WELCH.

SAFETY CUT-OFF DEVICE FOR FUEL OIL BURNERS.

APPLICATION FILED OCT. 26 1914.

1 ,1 83,786; Patented May 16, 1916.

Fig. i.

WI T/VESSES: IIVVEIVTOR g/zzweu OK eorge A. Wlch ATTORNEY were supplied by gravity showing an embodiment of GEORGE A. WELCH, 0F SEATTLE, WASHINGTON.

SAFETY GUT-OFF DEVICE FOR FUEL-OIL BURNERS.

Specification of Letters Patent.

Patented May is, 1916.

Application filed dctober 26, 1914. Serial No..868,612.

To all whom it may concern:

Be. it known that I, GEORGE A. WELCH, a citizen of the United States, residing at Seattle, in the county of King and State of lVashingtomhave invented certain new and useful Improvements in Safety CutOif Devices for Fuel-Oil Burners, of which the following'is a specification.

This invention relates to improvements in safety cut-off devices for fuel oil burners as shown and described in the prior patent application, Serial No. 866,576, filed by F ay A. Ardron and myself on date of October 1a, 1914.

in some types of fuel oil burners the oil is supplied to a distributing head in the furnace under pressure, where it is consumed. As shown inv the drawings, the oil is supplied to the head by a pump driven by a motor. If the fire is by any means extinguished, the motor and pump would continue to operate, thus filling the furnace with unconsumed oil, andmaking it diflicult and dangerous to rekindle the fire.

l tis my object in the present invention to provide means whereby the oil-supply may be cut 0% before such a condition obtains. In said previous patent application, Serial No. 866,576 we have shown means whereby the motor may be stopped, thus stopping the pumping of the oil, when the fire is extinguished. r i

In the present invention I show means which may be used independently or in combination with the first means, whereby the oil supply itself is cut off directly. This would be of particular advantage if the oil to the head, although I have shown a pump as the means for supplying the oil.

n the accompanying drawings, I have shown my invention in its present preferred form.

It is to be understood that I do not wish to confine myself to any particular type of oil burner, but that this may be of any suitable construction. I

In the accompanying drawings, Figure 1 is a longitudinal section through a furnace my invention in side elevation. Fig. 2 is a detached side elevation and partial section of a part of my improved apparatus in different position to that shown 1n Fig. 1.

A distributing head 1 is installed in the furnace 2, and has a hollow shaft 3 extend- This breaks ing downwardly to a gear-box 4. A motor 5 is adapted to turn shaft 3 through shaft 7 and bevel gears (not shown) in gear box Oil is supplied to the head 1 under pressure by means of pump 9, driven by motor 5. The oil flows through pipe 10, through gear box 4 and up the hollow shaft 3, where it is flung out in an atomized condition, centrifugal force from the head 1, and consumed.

If the fire in the furnace 2 is extinguished accidentally, the motor and pump would continue to operate, and the oil would soon flood thefurnace. To guard against this, I provide a gutter 11 in the floor of the furnace and surrounding head 1. The overflow oil collects in this gutter, and when sulficient oil has been collected it begins to flow' through strainers 13 and down-pipes 14 to a collecting pipe 16. The oil is then lead ofi through a discharge pipe 17 Near the discharge end of pipe 17 is a balance arm 19. On one end of this arm is an insulated switch blade 20, which is adapted to contact with terminals 21, which are in the motor circuit, which is normally closed. An adjustable weight 23 may be provided to keep this end of arm 19 down, and keep thev circuit closed. On the other end of the arm 19, and directly under the discharge end of pipe 17, is provided a removable receptacle 24. This is held in place by clips 25. When the oil which has collected in the gutter 11 flows out through pipe 17, as described, it falls into receptacle 24. After a short time the weight of this oil overcomes the weight of the other end of the arm 19, and causes it to rise.

the circuit of the motor, stopping the motor 5 and pump 9.

All of the above described devices are substantially the same as shown and described in said patent application Serial No. 866,576.

It is desirable that the oil supply to the pump be cut off immediately and positively as soon as the motor is stopped. To this end I provide a needle-valve 26 on the main feed-pipe 27, near the balance arm mechanism. An upstanding post 28 is secured on the valve parallel to the valve steam. 29, and a rod 30 is pivoted to the upper ends of the valve-stem 29 and post 28. en the outer end of rod 30 is free, it acts as a lever to and forces the point 31 of the stem firmly forming a knife switch down on seat 32. An ad- I friction roller ficient momentum to cause v ers, in combination,

' fuel supply justable weight 34 may be mounted on rod 30 if desired. hen the outer end of rod 30 is raised, however, this raises point 31 from seat 32, and opens the valve.

A standard 35 is provided near the balance arm 19, and to this an arm 37 is pivoted intermediate its length. To the lower end of arm 37 a bar 39 is adjustably secured by a thumb screw 40. This bar 39 is provided at its outer end with a bearing plate 41 which is adapted to be struck by an anti- 42 secured on balance arm 19 by means of pin 43, when the receptacle 24 is depressed by the weight of the oil. The upper end of arm 37 isv bent back toward the pivot point and a socket 44 is provided for the reception of the outer end of rod 30. This socket has a sloping back wall 46,'whereby the rod 30 automatically adjusts itself and bar 37 to the correct position, when the end of rod 30 is placed therein. Rod 30 and arm 37 should be so balanced that the bearing plate 41 is held a slight distance above roller 42,'which strikes it after said arm 19 has attained some impetus. Socket 44 should have only a small bearing surface for rod 30, so that the rod will be released by a slight blow of roller 42.

The operation of the device is as follows: If the fire in the furnace is accidentally extinguished, the oil continues to flow, but collects in the gutter 11 and flows from thence into receptacle 24, as has been described' When sufficient oil collects in receptacle 24 to overbalance the other end of arm 19, it is lowered, and the motor circuit is broken at 21. This stops the motor and pump. At the same time roller 42 in rising, strikes bearing plate 41, and gives a luck to arm 37. This withdraws the support of socket 44 from the end of rod 30, and the rod drops, closing the valve as before described. In this way both the motor and the are positively cut 0 The motor, however, has sufit to give the head 1 a number of turns, freeing the distributing head 1 and the hollow shaft 3 of the oil.

Having claim, is-- 1. In a safety cut-off for liquid fuel burna distribution head, a

same time.

described my invention, what I said two terminals in the motor circuit on gutter surrounding said head and adapted to collect the overflow balance arm, a receptacle on one end of said arm and normally held in raised position, and adapted to receive the overflow from said head, a main feed pipe for supplying fuel to said distributing head, a sliding valve in saidpipe, a post projecting upwardly from said valve, a rod pivoted to said post and the stem of said valve, a pivoted arm, and a socket carried by one end of said pivoted'arm adapted to support an end of said rod, the other end of sai pivoted arm being adapted to said balance arm when actuated by the overflow from said distributing head, whereby the rodis unseated from said socket and the valve-automatically closed. p 2. In a safety cut-off for liquid fuel burners, in combination, a distributing head, a pump supplying fuel to said head, a motor adapted to drive said pump, an electric circu'it including two switch terminals connected to the motor, means for. collecting the overflow from said distributing head, abalance arm having a switch blade connecting one end, a projecting roller on the same end, a receptacle on the other end adapted to receive the overflow from said distributing head, and normally held in raised position, a main feed pipe supplying fuel to said pump, a needle-valve in said pipe, a post extending upwardly from said valve, a rod pivoted at one end to said post and pivoted to the stem of said valve intermediate its length, a socket for the other end of said rod, a pivoted lever arm, said socket having a sloping back wall and being attached to one end of said pivoted lever arm, and an adjustable bar secured to the other end of said lever in position to be struck by the roller on said balance arm when actuated by the overflow whereby said motor is stopped and sai valve is closed, to cut off the supply of fuel to the distributing head. 1

Signed at Seattle, Wash this 9th day of be struck by 4 from said distributing head, I 

